Tire deflation indicator for automotive vehicles



March 23, 1954 L.. SELLARDS 2,673,261

TIRE DEEEATION INDICATOR FOR AUTOMOTIVE VEHICLES Filed April 4, 1952IIA-2 INVENTOR LYLE LeLLAnos WFM/)Mm f ,0mm

ATTORNEYS Patented Mar. 23, 1954 TIREl DEFLATION INDICATOR FORAUTOMOTIVE VEHICLES Lyle L. Sellards, Sanv Antonio, Tex. ApplicationApril 4, 1952, serial 10.280554 2 claims. (c1. 20o-61.24)

This invention relates to tire deation indicators 'for `automotivevehiclesv and more particularly to electrically energized apparatus forindicating a low pressure condition in any of the pneumatictiressupporting a vehicle on which thefapparatus is installed.

It is among the objects of the invention to provide an improved tire`deilation indicator for an automotive vehicle which indicatorcan beeasily installed in multiple on an automotive vee hicle so tha-t `one'indicator is located adjacent each of the l'supportingtires `of thevehicle, and electrically' connected to a common signal device toprovide a war-ning signal in the event of deflation of any one-ofthevehicle tires; which contacts 'the ground 4or roadway when theassociated tire is dellated or dangerouslyv underinflated but is ofresilient construction to avoid damage by Asuch contact; which issubstantially concealed by the associated vehicle Wheel and does notvvdetract from the appearance of the vehicle; which is effective toprovide a ground connection Tor vthe energizing circuit of the .signaldevice when the corresponding tire is deflated; and which is simplea-'ndfdurable in construction, economical to manufacture and install,and positive an eiectivein operation.

Other objects and advantages will 'become apparen-t from a considerationof the following description :and the appended claims in conjunctionwith the accompanying drawing wherein:

Figure .l is a fragmentary elevational view of anaut'omotive vehicleshowing a tire -deation indicator illustrative of the inventionoperatively mounted on the vehicle adjacent one of the vehiclesupporting tires;

Figure 2 is a cross sectional view on the line 2--2 of Figure 1;

Figure 3 is a fragmentary cross sectional view on the line 3-3 of Figure2; and

Figure 4 is a wiring diagram for the indicating apparatus.

With continued reference to the drawing, the numeral I generallyindicates a. vehicle axle carrying a spring II which supports thevehicle frame from the axle and the numeral I2 generally indicates thevehicle wheel mounted on the axle It! and equipped with a pneumatic tireI3.

The tire deflation indicating device comprises a clamp I5 in the form ofan elongated strip of flexible sheet material, such as sheet metal,having apertures I5 spaced apart longitudinally thereof and having adisc I'I secured to one Side adjacent the midlength location thereof.

The clamp strip I5 is adapted to extend around y2 the vehicle axle I0and embracingly engage the axle and a clamp screw VI5 is insertedthrough registering apertures `in. the strip at the `upper side olf theaxle and firmly binds the clamp strip around the axle with thedisc I'Ifirmly secured against the underside ofthe axle.`

While the clamp is `shown as extending around and secured to a vehicleaxle, it is to vbe understood that it may be secured to other vehicleparts such as la front wheel spindle or suspension bar, a tie rod or aspring.

A bolt I8 is secured .at vone end to the disc Il centrally of the latterand extends through an aperture in the clamp strip 4I5 in a directiondownwardly from the associated axle IG.

A U shaped bracket 20 in the form of a strip of resilient metal issecured at one end to the disc Il by the bolt-I8. Asleevezor cover 2l ofelectrically insulative material encloses the portion of the bracketstrip adjacent the disc II and the bracket strip is provided near oneend thereof an aperture through which the bolt I3 extends. A sleeve '22of electrically insulative material extends *through the aperture in thebracket strip `in surrounding relationship to the bolt and a washerf2`3is disposed against the side of the bracket remote from the ydisc I1 andprovided With an aperture receiving the bolt I8. A nut 24 is threadedonto the lower screw threaded end of the b'o'lt I and compresses thecorresponding end portion ofthe bracket 2D between the disc I'I and thewasher 23.

The sleeve 2I of velectrically insulative material terminates short ofthe end of the bracket 25J remote "from the bolt I3 and the `bracketstrip 2D is provided near its end remote from the bolt .I8 with alongitudinally curved portion 25 having its concave side at the bottomside of the corresponding bracket leg.

A looped wire spring, generally indicated at 26, is secured at one endto the Washer 23 by suitable means, such as by being welded to thewasher as indicated at 2l, and this wire is curved to provide an outsidecoil 28 extending from the end of the wire attached to the washer 23 andan inside coil 29 within the outside coil 28. A straight portion or leg30 of the wire spring extends from the end of the inner coil 29downwardly and has its distal end positioned adjacent the side wall ofthe tire I3 and at an elevation such that it is clear of the ground orroadway when the tire is inated but comes into contact with the groundor roadway when the tire is defiated.

The end portion of the outer coil 28 adjacent the inner coil 29 passesbelow the curved portion 25 of the bracket 20 in spaced relationship tothe bracket such that it is out of contact with the bracket when theassociated tire is fully inated but is forced upwardly into electricallyconducted contact with the bracket when the tire is deflated and thedistal end of the straight leg 30 of the Wire spring comes into contactwith the ground or roadway on which the tire is supported.

As the wire spring 26, the washer 23, bolt I8, and disc I1 are all ofelectrically conductive material, when the Wire spring contacts thebracket 20 a ground connection is provided between the bracket 20 andthe axle I0 of the vehicle or other portion of the vehicle on which theclamp I is mounted. r

A signal device 3|, such as an'electric lamp, is mounted on the vehiclefor observation by the vehicle driver and is connected at one sidethrough a conductor 32 with one side of the ignition switch 33 of thevehicle. The other side of the ignition switch is connected through aconductor 34 and ammeter 35 with one side of the vehicle battery 36 theother side of which is grounded through the vehicle frame, as indicatedat 31. A conductor 3B leads from the other side of the signal lamp 3|and it is apparent that when a ground connection is made between theconductor 38 and the vehicle frame the lamp 3l will be illuminated.

The conductor 38 is connected by branch conductors 38a, 38h, 38e and 38dto the several brackets; as indicated at 20a, 20h, 20c and 20d in Figure4. When any one of the wire springs, as indicated at 26a, 2Gb, 26e and26d contacts its associated bracket a ground connection is provided forthe conductor 38 and an energizing circuit is thereby established forthe signal lamp 3| so that the lamp will be illuminated and Warn thevehicle driver of the deflation of one of the vehicle tires.

The invention may be embodied in other specie forms without departing`from the spirit or essential characteristics thereof. The presentembodiment is, therefore, to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are, therefore, intended to be embracedtherein.

What is claimed is:

1. A switch for a tire deflation indicator for an automotive vehicle lcomprising an adjustable clamp adapted to embraclngly engage astrucvnear said other end of the latter and contacting said bracket toprovide a ground contact when said other end of the spring engages aroadway, said Wire spring comprising a length of resilient wirelongitudinally curved to provide an outer coil `extending from one endthereof, an inner coil disposed within said outer coil and a straightleg extending from the end of said inner coil remote from said outercoil, said wire spring being attached at said one end thereof to saidmeans connecting the bracket to the clamp and having a portion of theouter coil thereof disposed adjacent the end of said bracket remote fromsaid clamp.

2. A switch for a tire deflation indicator for an automotive vehiclecomprising a clamp adapted to embracingly engage a structural part of avehicle adjacent a vehicle tire, a U-shaped bracket fabricated ofresilienty material and positioned in a vertical plane below said clampwith its legs horizontally disposed and spaced vertically from eachother and its bight vertically disposed, means securing the leg of saidbracket adjacent said clamp to the latter, means electrically insulatingsaid bracket from said clamp, and a vertically disposed looped wirespring secured at the upper end to said means securing the leg of thebracket to the clamp and having the lower end adapted to contact aroadway upon deilation of `an associated vehicle tire, said springhaving a portion intermediate its ends and contacting the other legofsaid bracket to provide a ground contact when the lower end of thespring engages a roadway.

LYLE L. SELLARDS References cited in the fue of this patent UNITEDsTATEs PATENTS Number Name Date 1,646,164 Moscate Oct. 18, 19272,191,205 Rogers Feb. 20, 1940 2,213,782 Kite Sept. 3, 1940 2,258,334Miller i Oct. 7, 1941

